Abstract:
A method for forming fin field effect transistors for complementary metal oxide semiconductor (CMOS) devices includes filling, with a dielectric fill, areas between fin structures formed on a substrate, the fin structures including a silicon layer formed on a SiGe layer; removing the SiGe layer of a first region of the fin structures by selectively etching the fin structures from the end portions of the fin structures to form voids; exposing the silicon layer of the fin structures in the first region and a second regions; and thermally oxidizing the SiGe layer in the second region, forming SiGe fins on a second dielectric material in the second region and silicon fins on the first dielectric material in the first region.
Abstract:
A modified silicon substrate having a substantially defect-free strain relaxed buffer layer of SiGe is suitable for use as a foundation on which to construct a high performance CMOS FinFET device. The substantially defect-free SiGe strain-relaxed buffer layer can be formed by making cuts in, or segmenting, a strained epitaxial film, causing edges of the film segments to experience an elastic strain relaxation. When the segments are small enough, the overall film is relaxed so that the film is substantially without dislocation defects. Once the substantially defect-free strain-relaxed buffer layer is formed, strained channel layers can be grown epitaxially from the relaxed SRB layer. The strained channel layers are then patterned to create fins for a FinFET device. In one embodiment, dual strained channel layers are formed—a tensilely strained layer for NFET devices, and a compressively strained layer for PFET devices.
Abstract:
A method for channel formation in a fin transistor includes removing a dummy gate and dielectric from a dummy gate structure to expose a region of an underlying fin and depositing an amorphous layer including Ge over the region of the underlying fin. The amorphous layer is oxidized to condense out Ge and diffuse the Ge into the region of the underlying fin to form a channel region with Ge in the fin.
Abstract:
A method for forming fins includes growing a SiGe layer and a silicon layer over a surface of a bulk Si substrate, patterning fin structures from the silicon layer and the SiGe layer and filling between the fin structures with a dielectric fill. Trenches are formed to expose end portions of the fin structures. A first region of the fin structures is blocked off. The SiGe layer of the fin structures of a second region is removed by selectively etching the fin structures from the end portions to form voids, which are filled with dielectric material. The silicon layer of the fin structures is exposed. The SiGe layer in the first region is thermally oxidized to drive Ge into the silicon layer to form SiGe fins on an oxide layer in the first region and silicon fins on the dielectric material in the second region.
Abstract:
A method of forming a finFET transistor device includes forming a crystalline, compressive strained silicon germanium (cSiGe) layer over a substrate; masking a first region of the cSiGe layer so as to expose a second region of the cSiGe layer; subjecting the exposed second region of the cSiGe layer to an implant process so as to amorphize a bottom portion thereof and transform the cSiGe layer in the second region to a relaxed SiGe (rSiGe) layer; performing an annealing process so as to recrystallize the rSiGe layer; epitaxially growing a tensile strained silicon layer on the rSiGe layer; and patterning fin structures in the tensile strained silicon layer and in the first region of the cSiGe layer.
Abstract:
A method of making a structurally stable SiGe-on-insulator FinFET employs a silicon nitride liner to prevent de-stabilizing oxidation at the base of a SiGe fin. The silicon nitride liner blocks access of oxygen to the lower corners of the fin to facilitate fabrication of a high-concentration SiGe fin. The silicon nitride liner is effective as an oxide barrier even if its thickness is less than about 5 nm. Use of the SiN liner provides structural stability for fins that have higher germanium content, in the range of 25-55% germanium concentration.
Abstract:
A method for channel formation in a fin transistor includes removing a dummy gate and dielectric from a dummy gate structure to expose a region of an underlying fin and depositing an amorphous layer including Ge over the region of the underlying fin. The amorphous layer is oxidized to condense out Ge and diffuse the Ge into the region of the underlying fin to form a channel region with Ge in the fin.
Abstract:
A substrate layer formed of a first semiconductor material includes adjacent first and second regions. Fin structures are formed from the substrate layer in both the first and second regions. At least the side walls of the fin structures in the second region are covered with an epitaxially grown layer of second semiconductor material. A drive in process is performed to convert the fin structures in the second region from the first semiconductor material to the second semiconductor material. The first semiconductor material is, for example, silicon, and the second semiconductor material is, for example, silicon germanium or silicon carbide. The fin structures in the first region are provided for a FinFET of a first (for example, n-channel) conductivity type while the fin structures in the second region are provided for a FinFET of a second (for example, p-channel) conductivity type.
Abstract:
A method of forming a finFET transistor device includes forming a crystalline, compressive strained silicon germanium (cSiGe) layer over a substrate; masking a first region of the cSiGe layer so as to expose a second region of the cSiGe layer; subjecting the exposed second region of the cSiGe layer to an implant process so as to amorphize a bottom portion thereof and transform the cSiGe layer in the second region to a relaxed SiGe (rSiGe) layer; performing an annealing process so as to recrystallize the rSiGe layer; epitaxially growing a tensile strained silicon layer on the rSiGe layer; and patterning fin structures in the tensile strained silicon layer and in the first region of the cSiGe layer.
Abstract:
A method for forming fin field effect transistors for complementary metal oxide semiconductor (CMOS) devices includes filling, with a dielectric fill, areas between fin structures formed on a substrate, the fin structures including a silicon layer formed on a SiGe layer; removing the SiGe layer of a first region of the fin structures by selectively etching the fin structures from the end portions of the fin structures to form voids; exposing the silicon layer of the fin structures in the first region and a second regions; and thermally oxidizing the SiGe layer in the second region, forming SiGe fins on a second dielectric material in the second region and silicon fins on the first dielectric material in the first region.